MARCH 3RD, 1949 FLIGHT 243
BOMBERS
CROSSROADS
Boeing XB-47 Stratojet and Northrop XB-49 epitomize America's lead in jet-bomber design.
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Twin-Jet British "Medium" to Fly Soon : American Emphasis on
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I^OUR years ago, on behalf of the Air Ministry, the4 Ministry of Supply ordered a twin-jet medium-rangebomber. A full two and a half years elapsed, and
the mystery machine—presumed by then to have reached a
fairly advanced stage of gestation—was officially heralded
as "the forerunner of the new family of bombers." "Its
development," continued the M.o.S. release (in somewhat
dubious English), "both on the drawing board, in the
hands of the contractors' test teams and subsequently in
its training and operational stages in the R.A.F., will open
up a completely new era in bomber development and
(lying."
Another seventeen months elapsed—months in which six
types of American jet bomber and at least one of Russian
design were on trial; one of the American types was
delivered in quantity to the U.S.A.F. Now, at length, in
the Memorandum by the Secretary of State for Air to
accompany the Air Estimates for 1949-50, comes the
reassurance that Britain's first jet bomber is "expected to
tty in the very near future."
That when finally put to the test the new machine will
prove worthy of the name linked with it in the foreign
Press is not to be doubted, especially in view of the fact
that it has taken much longer to design and produce than
the Boeing XB-47, of 125,000 lb designed gross weight.
VVith its six underslung turbojets, 35-degree swept-back
wing and tail, and tandem undercarriage, the Boeing was
completed 15 months after the first work order was released
to the factory. On February 8th this year the protoype
dew from the State of Washington on the west coast of
America to Washington in the District of Columbia—a dis-
tance of some 2,290 miles—in 3 hours 46 minutes, averaging
more than 607 m.p.h.
Speculation as to the characteristics of the new British
!>omber would be premature, but the type is unlikely to
prove so radical in design as the XB-47. It may be com-
parable, rather, with the North American B-45. the first
B 3
example of which flew almost exactly two years ago and
which has already been issued in some? quantity to American
bomber units.
Welcome as the new British type will be, its deficiencies
in range have long been appreciated, for in September,
1946, an order was placed for a machine described officially
as a heavy bomber of longer range, but with a very similar
performance. Even this advanced type could not satisfy
Air Staff demands, and the Ministry of Supply has been
working with the Industry towards the attainment of greater
speed, range and operating height. A large amount of
wind-tunnel work has been undertaken to arrive at the most
efficient plan forms for the wings of future bombers, and
represented among the new types of "exceptionally high
performance," referred to by the Secretary of State'in his
Air Estimates Memorandum, may be wings of delta form,
or cranked iu shape, with certain sections having a sharper
sweep-back than others. One or more of the new designs
may be of the flying-wing type.
Deceptive Terminology
A cautionary word is called for by the official description
"heavy" as applied to Britain's new jet-bomber projects.
In the U.S.A. only the 278,000-lb Brabazon-size Convair
B-36 is so styled, the 125,000-lb XB-47 Stratojet and
213,000-lb Northrop YB-49 Jetwing being categorized as
"medium," and the 83,000-lb North American B-45 as a
" light " bomber. In size and weight Britain's " heavies"
will probably match the Northrop "Wing" more closely
than the B-36.
Until America can develop heavy jet-propelled bombers,
capable of ranges of the order of 10,000-12,000 miles, she
will continue to build piston-engine or turboprop types,
slower than the jets, but greatly exceeding in range even
the Northrop YB-49, which is generally credited with 5,000
miles.
Recent reports that funds are to be diverted from jet